I drive a 2013 Ford F150 FX2 with a 5.0 Coyote in it, running a recent tune up, K&N filter, fuel system cleaned; towing my bug it gives me 10.8 MPG running 75 MPH on the highway and a about a tenth or two short of 20 MPG running solo on the highway.
I towed to Bois D'arc this week and was able to run back roads all the way their and all the way back @ 55 MPH about a 40 mile trip one way and that yielded 13.8 MPG. I reset the MPG/Trip meter every time I tow my boat and after I get home from a fishing trip. Just wondered if any of y'all were seeing this. I can remember when the national speed limit was 55 MPH I was getting around 14 MPG towing my previous bass boats with trucks and SUV's that would average around 20 to 24 MPG minus the boat.

My trip to Bois D Arc this week pulling my 21 feet Champion with 5.3 GMC 4x4 averaged 13mpg pulling at 70-80mph , 81 miles 1 way, obviously mileage increase dramatically at lower mph such as 55-60.

I average around 12 pulling and 17 without.

2022 F250 6.7 Powerstroke.

I get around 9-1/2 towing and 11 empty. But it is a fun truck to drive.

I've never checked. I am gonna pull my boat no matter what the mpg is. I knew going in that buying a truck and using it was not gonna save me money. I just know it's comfortable to drive and pulls the boat well.

17.5 pulling from Amarillo to Ute lake in NM last week. About 220 miles round trip running with cruise set on 76 mph.
This 3.0 ltr baby Duramax doesn't do as well as my first one but still gets around 28 mpg highway with no trailer.

89 dodge ramcharger,94 ,98,2001,2006 chev/GMC pickups have all got between 11 and 13 mpg mileage for me at 65-70 mph highway speeds..18-20 mpg highway without boat.....made couple 2200 mile trips to Falcon with a buddy in his Toyota tundra and got 8-10 mpg....

22 F-150 with 3.5 eco boost. Bout 9 or 10 at 80 mph pulling the Skeet. Less if I’m in a hurry.

Same truck pulling FX 21. 17.5 on average. I saw 19.5 going to LBJ two weeks ago. Downhill made a difference. 17.5 coming home on Masters Sunday. Love the Baby Max

2023 GMC AT4X towing my Phoenix between 70-75. Trip computer shows around 3500 miles towing with an average of 9.6

17 mpg on a 230 miles trip , chevy 3.0 diesel .

11-12 mpg with boat. 21 to 23 mpg without at 65 MPH. 2018 Silverado 5.3L gas.

3.0 Duramax Suburban 17 pulling boat, 27 highway no boat.

55mph in Texas? Even on back roads, was there a line of cars behind you? In today's world, if they lowered to 55mph, that means you'll be driving 40-45mph behind a RV or someone headed to a casino.

If you live in Louisiana this is the norm..... Been on a couple of roads in LA and 55 was too fast for the road conditions.

#s posted are all with conditions that are unknown,